A Broken Chord

 is a quest in Tyranny.

Synopsis
The Voices of Nerat has asked you to go to the Blade Grave and bring back Graven Ashe's daughter, Amelia. She is being held captive at Sentinel Stand Keep, and the Voices needs her as a hostage to advance the Chorus agenda in the region.

Walkthrough

 * Head to Trapper's Junction and talk to Jagged Remedy.
 * Head to the entrance to the camp and talk to the Bronze Armiger. Mattias will emerge and talk to you offer to enter the camp and give an informed opinion, enabling you to enter unmolested.
 * Head south-west to find Irentis arguing with Mattias. Listen to them argue. Use Athletics 25 to convince Mattias to retain composure. Irentis will storm away regardless, insulting his commander.
 * Talk to Mattias about conscription. He will ask for a token of good faith from the Chorus. With a Diplomat background or Lore 40, you can ask him to provide a token of good faith first. You can ask for a blood offering, an oath of fealty, or with Subterfuge 40/45 a bribe (20/100 rings).
 * In turn, he will ask for Jagged Remedy to release the Unbroken prisoners taken in the last battle. Irentis will hassle you on the way back, but otherwise stay put. Talk to Remedy. He will naturally refuse to budge.
 * If you convinced Mattias to make a gesture of his own, particularly the blood offering, Remedy will be impressed and you'll get to choose between Unbroken and Disfavored for release.
 * Return to Mattias. If you arranged for the release of Unbroken prisoners, Mattias will acquiesce to the conscription, leading to Irentis rebelling against his authority. Now you get to talk him down:
 * Lore 40 allows you to call him out on his nihilistic death seeking.
 * With Verse you can teach Irentis a lesson in humility.
 * With the Diplomat or Soldier background you can point out that Irentis is disgracing himself and the people who serve with him.
 * Otherwise, you can stall for time using regular dialogue options, but everything comes to blows regardless.
 * Return to Jagged Remedy once Irentis is dead. Head to Sentinel Stand and meet Mattias (now with a new nickname) outside the wind wall. Murder the Bane and talk to Janos.
 * Irentis drops some notes which unlocks the Infested Oldwalls, allowing you to retrieve Dauntless.
 * Janos will be taken aback by Mattias' conversion, but undaunted. Ask him about a way into Sentinel Stand, then talk to Mattias. Head to the Rust Canyons, now unlocked.

Betray Alliance
The only opportunity to betray the Chorus during the Blade Grave quest chain is during your initial conversation with Jagged Remedy, before agreeing to recruit Mattias. Betrayal here will allow you to shorten your time spent at the Blade Grave, as Mattias will drop an unsent missive to Gregos, which unlocks the Oldwalls Breach. Irentis drops his notes which unlocks the Infested Oldwalls.

As such, you'll skip both Duskwatch Fort and Rust Canyons.